Kalshi Sets $17.9B Record May as World Cup Lifts Polymarket US to Weekly High

Kalshi closed May with $17.91 billion in notional quantity, its ninth consecutive month-to-month document and a 21% soar from April’s then-record $14.81B, in accordance to DeFi Rate’s prediction markets volume tracker. Polymarket posted $7.08 billion in the identical month, representing a 21% decline from its $10.57B March peak and its lowest month-to-month whole since January. The two platforms had been heading in reverse instructions going into June, which can see the beginning of fairly presumably the biggest sports activities betting catalyst to date with the 2026 World Cup kicking off.

Apart from notional quantity, a transaction hole can also be forming between the highest two prediction market platforms. Kalshi processed 111 million transactions in May, up from 94 million in April. Polymarket processed 69 million, down from 87 million, giving Kalshi a 61% transaction benefit, the widest margin since DeFi Rate started monitoring each platforms. That lead first opened in April, when Kalshi’s depend eclipsed Polymarket’s for the primary time.

Two Kalshi combo contracts, parlay-style multi-leg sports activities markets on the NBA finals, landed within the platform’s high 20 markets by buying and selling quantity during the last seven days, one other sign for the place prediction market exercise is concentrating. Sports and Exotics collectively accounted for 84% of Kalshi’s weekly notional through the week of May 25 and 85% through the week of June 1. The newest quantity information reiterates the significance of sports activities markets together with parlays within the general prediction market ecosystem.

May quantity highlights: Sports, parlays and a widening platform break up

Kalshi’s May quantity combine was closely concentrated in sports activities but once more. During the week of May 25, Sports accounted for $2.38B and Exotics, Kalshi’s parlay-style combo contracts, added $1.17B, collectively representing 84% of Kalshi’s weekly notional quantity, in accordance to monitoring from Dune analytics. Crypto contributed $527M. Everything else, together with Elections at $44.6M, Politics at $9M, and Economics at $11.6M, was marginal by comparability.

Exotics first crossed $1B in weekly notional quantity within the week of April 20. The class now commonly surpasses that threshold, trending up particularly throughout key occasions just like the NBA Finals. Kalshi’s Exotics development has been one of many extra consistent volume trends of 2026, and the looks of two combo contracts within the high 20 markets by buying and selling quantity final week, alongside the NBA Finals champion and LA mayoral race, displays how mainstream the product has develop into on the platform.

Polymarket’s May combine regarded completely different. During the week of May 25, Sports led at $952M however Politics ($242M), Trump markets ($99M), and Crypto ($297M) every carried actual weight. The extra balanced distribution throughout classes, with significant politics and crypto publicity, stays the clearest structural differentiator between the 2 platforms. Polymarket trades in another way than Kalshi, and May’s information makes that distinction as clear as ever.

Week of June 1: Kalshi climbs, Polymarket US breaks out

Kalshi notional quantity rose 6.1% to $4.46B within the week of June 1, its highest weekly whole since May 4. Exotics climbed to a brand new tracked high of $1.32B (+13% week over week) pushed by the primary two video games of the NBA Finals. Elections surged to $115.8M from $44.6M the prior week, a 160% improve pushed by California governor primary and LA mayoral markets. Crypto on Kalshi reached $713M, up from $527M.

On Polymarket Global, the story was Crypto with Bitcoin’s latest sell-off and worth motion a predominant catalyst. The class greater than doubled from $297M to $664M week over week, lifting whole Polymarket notional quantity 14.4% to $1.91B. Politics remained vital at $169M, with Trump markets including $46M on high.

The Polymarket US quantity was the standout of the week. The US platform posted $882M in notional quantity, greater than double its $439M the prior week and the biggest weekly US whole in latest tracked information. Fourteen of Polymarket US’s high 20 markets by buying and selling quantity during the last seven days had been World Cup contracts, and the event hadn’t even kicked off but. The Mexico vs. South Africa opener on June 11 and the US vs. Paraguay match on June 12 had been each closing quickly as of this writing, with $1.9M and $902K in buying and selling quantity respectively.

Exchange fees moved in numerous instructions. Kalshi’s weekly charges fell 11.7% to $33.51M regardless of increased notional quantity, a sign of combine shift towards lower-margin contracts. Polymarket US charges rose 26% to $4.34M on the doubled quantity.

Polymarket Global charges rose marginally from $6.56M to $6.69M, a 2% WoW improve. Along with the platform’s 14.4% notional quantity achieve, the smaller charge proportion improve displays a decrease common charge price on the crypto-heavy combine driving a lot of the weekly quantity development. Total charges throughout tracked platforms got here to $46.06M for the week of June 1, down from $50.17M the prior week.

Top markets: NBA Finals, California primaries, and a World Cup takeover

Kalshi’s high 20 markets during the last seven days, by USD-at-trading-price quantity, had been led by the NBA championship winner market ($17.7M, Knicks 78%), LA Mayoral Election winner ($17.2M, Karen Bass 59%), and 2026 Men’s World Cup winner ($7.7M, France 16%). The NBA Finals sequence contract and two combo parlays additionally made the record, alongside California governor and LA mayoral major markets that generated a cluster of political quantity forward of June 2 primaries. The Fed’s June determination market positioned fifth at $3.6M, with the market pricing a 99% likelihood of no change.

Kalshi Top 10 Markets: Last 7 days (USD at buying and selling worth)

Polymarket’s high markets mirrored a extra international, current-events-driven viewers. World Cup Winner led at $287.8M with $18.1M in open curiosity, by far the biggest single market on both platform. Fed Decision in June ranked second at $19.1M with $6.3M in OI. The US-Iran peace deal ($14.4M), Democratic Presidential Nominee 2028 ($12.4M, Newsom 25%), and Presidential Election Winner 2028 ($9.8M, JD Vance 16% with $37.7M in open curiosity) rounded out the highest 5. Politics dominated the mid-list, with the Seoul mayoral election, California governor, French presidential election, and a number of Iran-related markets all showing within the high 20.

Polymarket Global Top 10 Markets: Last 7 days (USD at buying and selling worth)

Polymarket US was nearly solely World Cup. Nine of the highest ten markets by buying and selling quantity had been soccer contracts: Portugal winner ($2.1M), Mexico vs. South Africa ($1.9M), Spain winner ($1.1M), Mexico winner ($991K), France winner ($873K), and a number of group-stage winner markets. The NBA champion marketplace for New York positioned sixth at $942K, the one non-soccer contract within the high ten.

Polymarket US Top 10 Markets: Last 7 days (USD at buying and selling worth)

What to watch in June

Kalshi’s $4.46B within the week of June 1 places it on tempo for an additional month-to-month document, although sustaining that stage by way of a full month is a special problem than a single robust week. The NBA Finals (Knicks main San Antonio 3-0 getting into Game 4) and the Stanley Cup playoffs give sports activities markets sustained gasoline by way of mid-month with World Cup group-stage play persevering with for many of June. The Fed’s June 16-17 assembly is the first macro catalyst exterior sports activities.

The larger query for June is whether or not the marquee occasion delivers on DeFi Rate’s $2.5B World Cup volume forecast throughout the event. Polymarket US’s pre-tournament surge, doubling to $882M earlier than a match was performed, with 14 of its high 20 markets already tied to soccer, suggests the ceiling could also be increased if per-match engagement holds by way of the group stage and into the knockouts. The US opens towards Paraguay on June 12, which ranked seventh on Polymarket US by buying and selling quantity final week at $902K. US presently leads in odds at 50% in contrast to 24% for Paraguay and 29% for a draw (tie).

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